Solid, rapid-setting, rigid polyurethanes

ABSTRACT

Compositions which will rapidly set to produce solid, rigid polyurethanes without the use of a catalyst comprise an amine initiated polyether polyol such as triethanol amine, an organic aromatic polyisocyanate, such as toluene diisocyanate and a liquid modifier compound having a boiling point above about 150°C such as trichlorobenzene.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of application Ser. No. 405,244, filedOct. 10, 1973 which is a continuation-in-part of application Ser. No.327,630, filed Jan. 29, 1973 now abandoned, which is acontinuation-in-part of Ser. No. 221,784, filed Jan. 28, 1972 nowabandoned.

This invention relates to rapid-setting, rigid, polyurethanecompositions comprising an amine initiated polyol, an organic aromaticpolyisocyanate and a liquid modifier compound boiling above about 150°C.

Rapid-setting, rigid polyurethanes are known and taught in U.S. Pat. No.3,378,511 and in copending applications having serial numbers and filingdates of 179,149 filed Sept. 9, 1971; 195,498, filed Nov. 3, 1971 nowU.S. Pat. No. 3,726,827 and 191,343 filed Oct. 21, 1971 U.S. Pat. No.3,746,692.

Each of these disclose rapid-setting polyurethane compositions, but ineach instance, a catalyst for urethane formation is required.

It has now been discovered that rapid-setting, solid, rigid polyurethanecompositions can be prepared without the use of a catalyst or externallyapplied heat.

By the term "rigid" or non-elastomeric as used herein, it is meant thatthe compositions which when solidified or set have percent elongationvalues at the break point of less than 100 percent.

By the term "solid" as used herein, it is meant that the compositionswhen solidified or set have densities of at least 1 gram per cubiccentimeter.

The term "rapid-setting" as used herein means that the composition willrapidly solidify without the application of external sources of heat andcan be removed from a mold within 5 minutes and preferably within 3minutes from the time the reactants are mixed together. Upon removalfrom the mold, the products have sufficient strength to be handled andnormally have sufficient strength to be employed for their intendedpurpose; however, the physical properties, if desired, usually can beimproved by post curing at elevated temperatures.

The rapid-setting, solid, rigid polyurethane compositions of the presentinvention comprise

A. an amine initiated polyol having an equivalent weight of from about50 to less than about 250 and preferably from about 50 to about 200;

B. an organic aromatic polyisocyanate;

C. as a modifier compound, a liquid modifier compound having a boilingpoint above about 150°C selected from the group consisting ofhydroxyl-containing and non-hydroxyl-containing polyoxyalkylenecompounds, ester-modified polyoxyalkylene compounds, organic phosphates,organic phosphites, organic phosphonates, cyclic ethers, aromaticcompounds, partially hydrogenated aromatic compounds, organiccarbonates, chlorinated aliphatic compounds, cyclic sulfones, esters ofcarboxylic acids and mixtures thereof;

wherein components (A) and (B) are present in quantities so as toprovide an NCO:OH ratio of from about 0.8:1 to about 1.5:1 andpreferably from about 0.9:1 to about 1.2:1 and most preferably fromabout 0.95:1 to about 1.05:1, and component (C) is employed inquantities of from about 5% to about 60%, and preferably from about 15%to about 40% by weight based upon the combined weight of components (A),(B) and (C).

Suitable amine initiated polyols which are employed as component (A) inthe present invention include, for example, those prepared by reactingan alkylene oxide with an amine having from 3 to about 8 active hydrogenatoms.

Suitable amines include, for example, ammonia, ethylenediamine,1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopropane,1,6-diaminohexane, diethylenetriamine, triethylenetetramine,tetraethylenepentamine, pentaethylenehexamine, mixtures thereof and thelike.

Suitable alkylene oxides include, for example, ethylene oxide,1,2-propylene oxide, 1,2-butylene oxide, 2,3-butyleneoxide, styreneoxide, epichlorohydrin, epibromohydrin, epiiodohydrin, mixtures thereofand the like.

Suitable organic aromatic polyisocyanates which are employed ascomponent (B) in the present invention include, for example, any organicpolyisocyanate having 2 or more NCO groups per molecule and no othersubstituents capable of reacting with the hydroxyl groups of the amineinitiated polyoxyalkylene compounds employed as component (A) or thehydroxyl containing compounds employed as component (C). Suitable suchpolyisocyanates include, for example, 2,4-toluenediisocyanate,2,6-toluenediisocyanate, xylylenediisocyanate,p,p'-diphenylmethanediisocyanate, p-phenylenediisocyanate, naphthalenediisocyanate, dianisidine diisocyanate, polymethylenepolyphenylisocyanate, mixtures of one or more polyisocyanates and thelike.

Other organic isocyanates which are suitably employed and which are tobe included in the term organic aromatic polyisocyanate includeisocyanate terminated prepolymers prepared from the previously mentionedpolyols, amine initiated or hydroxyl initiated polyols, and aromaticpolyisocyanates.

What is meant by the term "organic aromatic polyisocyanate" is that thepolyisocyanate contains at least one aromatic ring.

Suitable polyoxyalkylene compounds which are employed as the liquidmodifier compound (Component C) include, for example,

1. a liquid, totally-capped or non-hydroxyl-containing block or randomlyformed polyoxyalkylene glycol represented by the general formula##STR1## wherein R and R' are independently selected from saturated andunsaturated hydrocarbon groups having from about 1 to about 6,preferably from about 1 to about 3, carbon atoms; R₁, R₂, . . . andR_(n) are independently hydrogen, an aryl group, an alkyl group orhaloalkyl group, said alkyl or haloalkyl group having from about 1 toabout 2 carbon atoms with the proviso that when R₁, R₂ . . . R_(n) is ahaloalkyl group, it is present in minor amounts, i.e., a ratio of fromabout 0 to about 10 percent of the total R₁, R₂ . . . R_(n) groups, andx₁, x₂, . . . x_(n) are integers, such that the boiling point of theliquid capped polyoxyalkylene glycol is above about 150°C;

2. a liquid partially capped, block or randomly formed polyoxyalkylenecompound represented by the general formula ##STR2## wherein R and R₁,R₂ . . . R_(n) are as defined in formula I above and x₁, x₂, . . . x_(n)are integers, the sum of which provides the partially cappedpolyoxyalkylene compound with a molecular weight of at least about 700;

3. a liquid, block or randomly formed polyoxyalkylene glycol representedby the general formula ##STR3## wherein R₁, R₂ . . . R_(n) are asdefined in formula I above and x₁, x₂ . . . x_(n) are integers, the sumof which provides the polyoxyalkylene glycol with an equivalent weightof at least about 700, and

4. a liquid, random or block polyoxyalkylene polyol having a hydroxylfunctionality of from 3 to about 8 represented by the general formula##STR4## wherein R₁, R₂ . . . R_(n) are as defined in formula I above, Zis the residue of an initiator compound having from 3 to about 8hydroxyl groups, x₁, x₂, . . . x_(n) are integers, the sum of whichprovides the polyoxyalkylene polyol with a hydroxyl equivalent weight ofat least about 500 and q is an integer having a value of from 3 to about8.

Suitable ester-modified polyoxyalkylene compounds which are employed asthe liquid modifier compound (Component C) include, for example, thoseliquid ester-modified polyethers having a boiling point above about150°C represented by the general formula ##STR5## wherein A is theresidue of an initiator or starting compound having from 1 to about 8hydroxyl groups, Z is the residue, excluding the carboxyl groups, of aninternal anhydride of a saturated or unsaturated acyclic aliphatic, asaturated or unsaturated cyclic aliphatic, or aromatic polycarboxylicacid, halogenated derivatives thereof and mixtures thereof, each R is asubstituent independently selected from hydrogen atoms, an alkyl radicalhaving from 1 to 20 carbon atoms, a halomethyl radical, a phenylradical, and a phenoxymethyl radical, an alkoxymethyl radical with theproviso that one of the R substituents must be hydrogen, R' is hydrogenor a saturated or unsaturated aliphatic group having from 1 to 20 carbonatoms, m has an average value of from about 1.0 to about 2.0, n has avalue from about 1 to about 5, x has a value from about 1 to about 8 andy has a value of 1 or 2 and wherein said ester-modified polyethercompound has a hydroxyl equivalent weight above about 500 when 3 or morehydroxyl groups are present and when 2 hydroxyl groups are present, anaverage equivalent weight of above about 700 and when zero or onehydroxyl group is present a molecular weight of above about 700.

Suitable initiators which are employed to prepare the liquidpolyoxyalkylene and ester-modified polyoxyalkylene modifier compounds(Component C) of the present invention include compounds having from 1to about 8 hydroxyl groups such as, for example, methanol, ethanol,propanol, butanol, ethylene glycol, propylene glycol, butylene glycol,1,6-hexane diol, glycerine, trimethylolpropane, pentaerythritol,sorbitol, sucrose, mixtures thereof and the like.

When the liquid modifier compound, component (C), is an ester modifiedpolyether polyol, the initiator compound may also be and is preferablyan adduct of the above mentioned initiator compounds and one or more ofthe following vicinal epoxide-containing compounds, i.e., the initiatorcompound is a polyoxyalkylene compound having 1 to 8 hydroxyl groups,preferably 2 to about 3 or 4 hydroxyl groups.

Suitable vicinal epoxide compounds which may be reacted with the abovementioned initiator compounds to prepare the modifier compounds(Component C) employed in the present invention include, for example,ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide, 2,3-butyleneoxide, epichlorohydrin, epibromohydrin, epiiodohydrin, styrene oxide,mixtures thereof and the like.

The liquid modifier compounds represented by formulae I-IV and methodsfor their preparation are well known in the art, e.g., U.S. Pat. Nos.2,448,644; 2,425,755; 2,782,240 and 2,520,611. Methods for thepreparation of the liquid modifier compounds represented by the formulaV are given in a copending application Ser. No. 67,233, filed Aug. 26,1970 by Robert W. McAda, Jr. for "ESTER-MODIFIED POLYETHER POLYOLS" andin U.S. Pat. No. 3,502,601.

Suitable aromatic compounds which are employed as the liquid modifiercompound having a boiling point above about 150°C (Component C) in thepresent invention include, for example, straight and branch chainaliphatic, alkoxy and halogen substituted benzenes, aromatic substitutedbenzene and aromatic ethers, such as, for example, propenyl benzene,propylbenzene, butylbenzene, ethyltoluene, butyltoluene, propyltoluene,diphenyl oxide, biphenyl, o-, m- and p-diethyl-benzene, dodecylbenzene,octadecylbenzene, bromobenzene, 1-bromo-3-chlorobenzene,1-bromo-4-fluorobenzene, 1-bromo-2-iodobenzene, 1-bromo-3-iodobenzene,1-chloro-4-fluorobenzene, o-dibromobenzene, m-dibromobenzene,o-dichlorobenzene, m-dichlorobenzene, 1,3-dipropoxybenzene,1-ethyl-4-propylbenzene, 1-fluoro-4-iodobenzene, 4-bromo-o-xylene,α-bromo-m-xylene, 4-bromo-m-xylene, α-chloro-m-xylene, 4-ethyl-m-xylene,5-ethyl-m-xylene, 2-bromo-p-xylene, α-chloro-p-xylene, 2-ethyl-p-xylene,2-ethyl-p-xylene, o-bromotoluene, m-bromotoluene, o-, m-, andp-chlorotoluene, tertiary butylstyrene, α-bromostyrene, β-bromostyrene,α-chlorostyrene, β-chlorostyrene, mixtures thereof and the like.

The above compounds are represented by the following general formulaprovided it is understood that such compounds represented by the formulaare liquids and have boiling points at atmospheric pressure above about150°C. ##SPC1##

wherein R₁, R₂ and R₃ are independently selected from an alkyl grouphaving from about 1 to about 18 carbon atoms, an alkenyl group havingfrom 2 to about 3 carbon atoms, a halogen, an alkoxy group, an aromaticgroup and hydrogen.

Other suitable aromatic compounds which are employed as the liquidmodifier compound (Component C) in the present invention include liquidmulti-ring compounds having a boiling point above about 150°C such as,for example, 1-chloro-naphthalene, 1-bromo-naphthalene, mixtures thereofand the like.

Suitable partially hydrogenated multi-ring aromatic compounds which areemployed as the liquid modifier compound (Component C) in the presentinvention include, for example, 1,4-dihydronaphthalene,1,2,3,4-tetrahydronaphthalene, mixtures thereof and the like.

Suitable organophosphorus compounds which are employed as the liquidmodifier compound, Component C, include, for example, organo phosphates,organo phosphites and organo phosphonates having boiling points aboveabout 150°C.

Organo phosphates, phosphites and phosphonates which are employed as theliquid modifier compound include those liquid compounds represented bythe formulae ##STR6## wherein R₁, R₂ and R₃ are independently selectedfrom the group consisting of alkyl, alkoxyaryl, aryloxyaryl, alkaryl,aralkyl groups and halogen substituted derivatives thereof. Y is oxygenor sulfur, X is a halogen, i.e., chlorine, fluorine, bromine or iodine,n has a value of 1 or 2. Suitable such compounds include, for example,tri-n-butyl phosphate, triethylphosphate, tricresylphosphate,tris-(beta-chloroethyl)phosphate, tris-(2,3-dibromopropyl)phosphate,butyl dichlorophosphate, 2-chloroethyl dichlorophosphate, ethyldichlorophosphate, diethyl fluorophosphate, bis(2-chloroethyl)fluorophosphate, dibutyl chlorophosphate, isoamyldichlorothionophosphate, ethyl dibromothiophosphate, 2-chlorophenyldichlorophosphate, 2-methoxyphenyl dichlorophosphate, 2-phenoxyphenyldichlorophosphate, 2-chloroethyl dichlorophosphite,tris(2-chloroethyl)phosphite, tributyl phosphite, tricresyl phosphite,triethyl phosphite, diethyl isoamylphosphonate, diethylethylphosphonate, dimethyl methylphosphonate, diethyl methylphosphonate,diisobutyl isobutylphosphonate, bis(2-bromopropyl)-2-bromopropanephosphonate.

The organo phosphorus compounds can be prepared by procedures describedin ORGANO-PHOSPHORUS COMPOUNDS, G. M. Kosolapoff, John Wiley & Sons,Inc., 1950.

Suitable liquid organic carbonates which are employed as the liquidmodifier, component C, in the present invention include the acyclic andcyclic carbonates represented by the formulae ##STR7## wherein each R₁and R₂ are independently aryl, alkyl (having from about 1 to about 6carbon atoms) or alkenyl groups (having from about 1 to about 6 carbonatoms) and substituted derivatives thereof and each R₃ and R₄ areselected from the same groups as R₁ and R₂ and hydrogen.

Suitable liquid acyclic organic carbonates which are employed in thepresent invention include, for example, bis(2-chloroethyl carbonate),di-n-butyl carbonate, butyldiglycol carbonate, cresyldiglycol carbonate,dibutyl carbonate, di-2-ethylhexyl carbonate, dimethallyl carbonatedinonyl carbonate and the like. The organic acyclic carbonate may beprepared by procedures given in U.S. Pat. No. 2,687,425.

Suitable liquid cyclic organic carbonates include, for example,propylene carbonate, butylene carbonate, styrene carbonate, mixturesthereof and the like. The cyclic organic carbonates may be prepared inthe manner described in Canadian Pat. No. 556,006.

Suitable cyclic polyethers which are employed as the liquid modifier(component C) include, for example, the cyclic tetramer of ethyleneoxide, cyclic pentamer of propylene oxide, cyclic tetramer of propyleneoxide, mixtures of the above and mixtures of cyclic pentamers and aboveof ethylene oxide and or propylene oxide. Any liquid cyclic polyetherhaving a boiling point above 150°C may be employed as the liquidmodifier in the present invention including cyclic polyethers preparedfrom butylene oxide, epichlorohydrin and the like.

The liquid cyclic polyether modifier compounds can be prepared byprocedures mentioned in "Cyclic Polyethers and Their Complexes withMetal Salts" by C. J. Pedersen, J. Am. Chem. Soc., Vol. 89, p.7017-7036, 1968, "Twelve-Membered Polyether Rings. The Cyclic Tetramersof Some Olefin Oxides" by R. S. Kern; J. Org. Chem., Vol. 33, p.388-390, 1968; British Pat. Nos. 785,229 and 1,108,921.

Suitable chlorinated aliphatic compounds having a boiling point aboveabout 150°C which are employed as the modifier compound in the presentinvention include, for example, such chlorinated aliphatic compounds ashexachlorobutadiene, tetrachlorobutadiene, 1,2,3,3-tetrachlorobutane,1,2,3-trichloropropene, polyepichlorohydrin diol having an equivalentweight above about 700 up to about 4000, chlorinated paraffins, e.g.,"Chlorowax" No. 40, 1-mercapto-3-chloropropanol-2,3-chloropropane-1,2-diol, 2-chloropropane, 1,3-diol,1,3-dichloro-2-propanol, mixtures thereof and the like.

Suitable cyclic sulfones which are employed as the liquid modifiercompound include the 5-membered cyclic sulfones such as, for example,3-methylsulfolane (3-methyltetrahydrothiophene-1,1-dioxide) and thelike.

Suitable esters of a carboxylic acid which are employed as component (C)in the present invention include those esters prepared from mono- andpolycarboxylic acids having from about 1 to about 20 carbon atoms suchas for example, phthalic, adipic, acetoacetic, formic, acetic, abietic,acids, and the like and wherein the ester portion contains from about 1to about 20 carbon atoms such as methyl, ethyl, propyl, butyl, hexyl,cyclohexyl, octyl, decyl, dodecyl, eicosyl and the like so long as thecarboxylic acid ester has a boiling point above about 150°C and is aliquid at room temperature.

These acid esters can be prepared by condensing an acid having fromabout 1 to about 20 carbon atoms with a saturated or unsaturatedaliphatic alcohol having from about 1 to about 20 carbon atoms, with theproviso that the ester product is a liquid and has a b.p. >150°C.

The term "liquid modifier boiling above about 150°C" includes eutecticmixtures of the previously described classes of compounds which aresolids at atmospheric pressure but said eutectic mixtures are a liquidat room temperature and atmospheric pressure which have boiling pointsabove about 150°C. Also included in the definition are those solidcompounds of the classes previously described which are dissolved in aliquid member of any of the described classes of compounds havingboiling points above about 150°C wherein the resultant solution is aliquid at standard conditions of temperature and pressure and haveboiling points at atmospheric pressure above about 150°C.

Other components including inert fillers such as, for example, sand,microballoons, glass fibers, asbestos, aluminum granules, siliconcarbide powder and the like, coloring agents, such as pigments and dyesincluding, for example, chromic oxide, ferric oxide, mixtures thereofand the like may be employed in the compositions of the presentinvention without detracting from the scope thereof.

Suitable materials from which adequate molds, for casting thecompositions of the present invention, may be prepared include polymerssuch as, for example, polyethylene, polypropylene, their copolymers andthe like, polyurethanes, polysiloxane elastomers, Mylar, curedpolyepoxides, mixtures thereof and the like.

It is preferred to employ relatively thin wall molds or molds having alow heat capacity or thermal conductivity. Heavy molds made ofrelatively high thermal conductivity materials such as aluminum, copper,iron or steel and the like may present curing problems, i.e., thereactants may not be readily demolded unless the mold is preheated toabout 50°-90°C, especially when casting relatively thin sections.However, high thermal conductivity materials such as copper or aluminumcan be employed as thin wall molds without preheating if the thermalcapacity of the mold is relatively low compared to the amount of heatliberated in the casting.

The compositions of the present invention are useful as, but notrestricted to such uses as, a casting material for preparing bearingsurfaces, annular spacers, game pieces, decorative objects, furniture orfurniture components, gears or other machine components, threadedprotective plugs and caps, and the like.

In some instances, a mixture of the components (A) and (B) are soincompatible that the reaction occurs very slowly (i.e., solidificationrequires more than 10 minutes). When this occurs, a modifier-compoundhaving a high dielectric constant measured at 20°C, and a frequency of 1× 10⁴ cycles per second of greater than 4 and preferably greater than 8,such as, for example, ethylacetoacetate, propylene carbonate,acetophenone, and dimethyl phthalate can be employed to render themixture compatible.

These compounds tend to render the components (A) and (B) morecompatible, in that they can be blended and will rapidly react to yielda fast setting solid that is demoldable in less than 5 minutes.

The modifier-compatabilizer compounds are employed in the range of fromabout 2.5 to about 60% by weight of the combined weight of components(A), (B) and (C) and such quantities are included as a portion of thetotal quantity of component (C) present in the composition.

If the time interval between addition of the polyisocyanate to the amineinitiated polyol and the "sudden solidification" of the formulations ofthe present invention is too short for a given application or situation,the delay time before solidification occurs can be increased by theaddition of a low equivalent weight (less than 200 equiv. wt.) liquid,non-amine initiated polyol having a hydroxyl functionality of 2 to 8,preferably having a functionality of 3 to 8.

The weight ratio of non-amine initiated polyol to the amine initiatedpolyol must be less than 2:1 and generally preferably less than 1:1.

If the delay time between blending of a given polyisocyanate and a givenamine initiated polyol and the solidification time is in the order ofabout 20 seconds, any addition of a non-amine initiated polyol willincrease the delay time before solidification and the addition of anequal weight ratio of non-amine initiated polyol can increase the delaybefore solidification up to about 120 seconds.

The following examples are illustrative of the present invention but arenot to be construed as to limiting the scope thereof in any manner.

In each of the examples and comparative experiments, all of thecomponents except the polyisocyanate were thoroughly blended togetherand then the polyisocyanate was rapidly blended into the mixture andimmediately poured into a polyethylene mold or a Mylar tray.

The compositions, setting and demolding times and properties of theproducts are given in the following table.

    __________________________________________________________________________    Example or                                                                    Comparative -Experiment                                                               Component A                                                                          Component B                                                                          Component C                                                                           Time*in Sec. to                                                                         Density                                                                            Other Properties or              No.     Type                                                                             Grams                                                                             Type                                                                             Grams                                                                             Type                                                                             Grams                                                                              Solidify                                                                           Demold                                                                             Grams/cc                                                                           Remarks                          __________________________________________________________________________    Ex. 1   A  26  A  30  A  30   15   30   1.16 Shore D hardness = 92            Comp.Exp.A                                                                            A  26  A  30  none                                                                             --   25   --   0.61 Swelled, cracked, distorted                                                   and                                                                           formed gross fissures or                                                      cracks.                          Ex. 2   B  35  A  30  B  30   25   70   1.08 Off white, opaque product.       Comp.Exp.B                                                                            B  30  A  30  none                                                                             --   --   --   0.59 Swelled and cracked.             Ex. 3   A  33  B  50  C  33   20   40   >1.0 Opaque, cream colored,                                                        solid.                           Ex. 4   A  52  A  60  C  60   20   40   1.16 Shore D hardness = 96,                                                        Tensile Strength = 7428 psi                                                   at                                                                            an elongation of 8%.             Ex. 5   A  52  C  92  D  60   35   50   >1.0 Tensile strength = 9765 psi                                                   at                                                                            an elongation of 10%.            Ex. 6   A  26  A  30  E  60   50   54   1.12 Shore D hardness = 79            Ex. 7   A  26  A  30  E  30   20   45   1.14 Shore D hardness = 88            Ex. 8   A  26  A  30  F  30   25   50   1.13 Shore D hardness = 73            Ex. 9   C  18  D  45  C  10   90   120  >1.0 Opaque, white solid                                    G  10                                                   Ex. 10  C  18  C  46  G  10   40   80   >1.0                                  Ex. 11  C  18  C  46  C  10   90   180  >1.0                                  Ex. 12  D  42  A  30  D  30   40   90   1.07 Shore D hardness = 89            Ex. 13  B  44  A  50  H  50   35   115  >1   Shore D Hardness                                                              = ˜85                      Ex. 14  A  26  A  30  I  30   20   40   >1   Shore D hardness = >80           Ex. 15  B  26  A  30  J  30   25   50   1.04 Shore D Hardness = >85           Ex. 16  A  30  A  35  K  35   20   60   >1   Shore D Hardness = >80           Ex. 17  B  26  A  30  L  40   20   50   >1   Shore D Hardness = >85           Ex. 18  B  40  A  46  M  30   20   60   >1   Shore D Hardness = >85           Ex. 19  B  26  A  30  N  30   20   40   1.06 Shore D Hardness = >80           Ex. 20  A  26  C  45  O  30   20   50   >1   Shore D Hardness = >80           Ex. 21  A  26  A  30  P  30   20   50   >1   Shore D Hardness                 __________________________________________________________________________                                                 = ˜85                       *The time was measured from the moment the polyisocyanate was blended int     the mixture.                                                             

The amine initiated polyols employed as component (A) in the precedingexamples and comparative experiments were as follows:

Type A was aminoethylethanol amine reacted with propylene oxide in amolar ratio of about 1:3 respectively having a hydroxyl equivalentweight of about 72.

Type B was the reaction product of diethylene triamine with propyleneoxide in a molar ratio of about 1:5 respectively and having an OHequivalent weight of about 76.

Type C was triethanolamine.

Type D was the reaction product of diethylenetriamine with propyleneoxide in a molar ratio of about 1:8 respectively and having an OHequivalent weight of about 115.

The polyisocyanates employed as component (B) in the preceding examplesand comparative experiments were as follows:

Type A was an 80/20 mixture of the 2,4-/2,6-isomers oftoluenediisocyanate having an NCO equivalent weight of about 87.

Type B was a dimerized diphenylmethane diisocyanate having an averagefunctionality of about 2.25 and an NCO equivalent weight of about 144.

Type C was a polymethylene polyphenylisocyanate having an averagefunctionality of about 2.6 and an NCO equivalent weight of about 134.

Type D was a prepolymer having a % free NCO of about 32 prepared byreacting an 80/20 mixture of 2,4-/2,6-toluene diisocyanate with thereaction product of glycerine with propylene oxide to an OH equivalentweight of about 87.

The modifier compounds employed as component (C) in the precedingexamples and comparative experiments were as follows:

Type A was trichlorobenzene.

Type B was the reaction product of glycerine with propylene oxide to amolecular weight of about 1500.

Type C was dioctylphthalate.

Type D was a mixed stream of aromatic-containing compounds containingpolyethylbenzenes as the residue stream obtained from the manufacture ofethyl benzene and having a typical composition by weight as follows:

3% triethylbenzene

11% tetraethylbenzene

1% pentaethylbenzene

3% bis-ethylphenylethane

8% ethylphenyl-phenylethane

13% 1,1-diphenylethane

61% higher boiling components

Type E was diphenylether.

Type F was a liquid chlorinated paraffin having a specific gravity ofabout 1.15, a viscosity at 25°C of about 25 poises and containing about40% by weight chlorine commercially available as Chlorowax No. 40 fromDiamond Alkali Co.

Type G was ethylacetoacetate.

Type H was a capped polyether polyol which was the reaction product ofallyl alcohol with a 50/50 mole % mixture of ethylene oxide and1,2-propylene oxide to an average molecular weight of about 1800 andsubsequently capped with methyl groups.

Type I was the reaction product of a glycerine initiatedpolyoxypropylene glycol having a molecular weight of about 3000 withthree moles of phthalic anhydride and then with ethylene oxide, theresultant ester-modified polyether polyol having an average OHequivalent weight of about 976.

Type J was tricresyl phosphate.

Type K was tri-n-butyl phosphite.

Type L was bis(2-bromopropyl)-2-bromopropane phosphonate.

Type M was the cyclic pentamer of propylene oxide.

Type N was tetrahydronaphthalene.

Type O was propylene carbonate.

Type P was 3-methyl sulfolane.

EXAMPLE 22

Components of the composition:

30 grams amine polyol, Type A

30 grams of the reaction product of glycerine with propylene oxide to anaverage molecular weight of about 260.

60 grams of dioctyl phthalate

60 grams of polyisocyanate Type A.

After rapidly stirring the polyisocyanate into a mixture of the othercomponents, the liquid mixture was poured into a 450 cc polyethylenebeaker. About 90 seconds after stirring in the TDI, the liquid mixturebegan to turn opaque and in another 30 seconds, this mixture hadsolidified into an opaque white solid. Four minutes after addition ofthe TDI, this cast rigid polymer was removed from the polyethylene mold.This tough dense opaque white casting was found to exhibit a Shore Dhardness greater than 80 and a density of 1.13 g/cc.

EXAMPLE 23

In each of the following experiments, the components were rapidlyblended together and then poured into a Mylar tray or into apolyethylene beaker. The compositions and results are given in thefollowing table.

    __________________________________________________________________________                   EXPERIMENT NUMBER                                                             Present Invention                                                                       Comparative Experiment                                               A    B    C    D    E                                         __________________________________________________________________________    2,4-toluenediisocyanate,                                                       grams         45   45   38.9 38.9  38.9                                      triethanol amine, gms.                                                                       17   17   11.1 0     11.1                                      hydroxyl initiated polyol,.sup.1                                               grams         0    0    0    38.9  0                                         trichlorobenzene,gms/%.sup.2                                                                 38/38                                                                              62/50                                                                              50/50                                                                              38.9/33                                                                             0                                         chlorinated biphenyl,                                                          48% chlorine,gms/%.sup.2                                                                    0    0    0    0     50/50                                     NCO:OH ratio   1.53:1                                                                             1.53:1                                                                             2.05:1                                                                             1:1   2.05:1                                    Solidification time                                                                          90 sec.                                                                            2 min.                                                                             still                                                                              still still                                                              liquid                                                                             liquid                                                                              liquid                                                             after                                                                              after after                                                              2 hrs.                                                                             2 hrs.                                                                              12 hrs.                                   demold time    3 min.                                                                             41/2 min.                                                                          N.D..sup.3                                                                         N.D.  N.D.                                      density, g/cc  >1   >1   N.D. N.D.  N.D.                                      __________________________________________________________________________     .sup.1 The hydroxyl initiated polyol was an adduct of glycerine and           propylene oxide to a molecular weight of about 260.                           .sup.2 % modifier is based upon the combined weight of the modifier, the      polyol and the polyisocyanate.                                                .sup.3 N.D. = not determined.                                            

I claim:
 1. A process for producing solid, rigid, polyurethane articleshaving a density of at least 1 g/cc, a percent elongation of less than100, and which can be demolded within a period of about 5 minuteswithout the addition of an external source of heat, which processcomprises1. admixing, in the absence of a catalytic quantity of acatalyst for urethane formation, the components of a compositioncomprisingA. an amine initiated polyol having an OH equivalent weight offrom about 50 to less than about 250; B. an organic aromaticpolyisocyanate; C. a liquid modifier having a boiling point above about150° C, said modifier consisting of a mixture, in any proportion, of atleast two members selected, in any combination, from the groupconsisting of
 1. organic phosphates, phosphites, or phosphonates,2.cyclic ethers,
 3. aromatic compounds or partially hydrogenated aromaticcompounds, such compounds being free of ester groups and groups reactivewith NCO groups,
 4. chlorinated aliphatic compounds,5. cyclic sulfones,6. organic carbonates,
 7. esters of carboxylic acids, 8.non-hydroxyl-containing polyoxyalkylene compounds,
 9. ester-modifiedpolyoxyalkylene compounds having an average hydroxyl equivalent weightabove about 700 when such compounds contain 2 hydroxyl groups, anaverage hydroxyl equivalent weight, above about 500 when such compoundscontain 3 or more hydroxyl groups and an average molecular weight aboveabout 700 when such compounds contain zero or 1 hydroxyl group; and 10.hydroxyl-containing polyoxyalkylene compounds selected from the groupconsisting ofa. such compounds having one or two hydroxyl groups permolecule and an average hydroxyl equivalent weight of at least about700; b. such compounds having from about 3 to about 8 hydroxyl groupsper molecule and an average hydroxyl equivalent weight of at least about500; wherein components (A) and (B) are present in quantities such thatthe NCO:OH ratio is from about 0.8:1 to about 1.5:1 and component (C) isemployed in quantities of from about 5% to about 60% by weight of thecombined weight of components (A), (B) and (C);
 2. placing the admixedcomposition into a suitable mold wherein said composition solidifieswithin less than about 5 minutes to a solid having a density of at least1 g/cc and a percent elongation of less than 100; and
 3. subsequentlydemolding the resultant article from the mold.
 2. The process of claim 1wherein components (A) and (B) are present in quantities such that theNCO:OH ratio is from about 0.90:1 to about 1.2:1 and component (C) ispresent in quantities of from about 15% to about 40% by weight of thecombined weight of components (A), (B) and (C) and wherein component (A)has an OH equivalent weight of from about 50 to about
 200. 3. Theprocess of claim 2 wherein components (A) and (B) are present inquantities such that the NCO:OH ratio is from about 0.95:1 to about1.05:1.
 4. The process of claim 3 wherein component (C) is a mixturecontaining 3-methylsulfolane, dioctylphthalate and tris-β-chloroethylphosphate.
 5. The process of claim 3 wherein component (C) is a mixturecontaining 1-chloronaphthalene, butyl oleate and 3-methylsulfolane. 6.The process of claim 3 wherein component (C) contains a mixture ofbis(2-bromopropyl)-2-bromopropane phosphonate, a chlorinated paraffin,diisodecyl phthalate, 1-chloronaphthalene and 3-methylsulfolane.
 7. Theprocess of claim 1 wherein component (A) is selected from the groupconsisting of triethanolamine, an adduct of diethylenetriamine withpropylene oxide and an adduct of aminoethylethanolamine with propyleneoxide.
 8. The process of claim 1 wherein component (B) is selected fromthe group consisting of 2,4-toluenediisocyanate,2,6-toluenediisocyanate, diphenylmethanediisocyanate, and mixturesthereof.
 9. The process of claim 1 wherein said mold is in the form of adecorative object.
 10. The process of claim 1 wherein said mold is inthe form of a furniture component.
 11. The process of claim 1 whereinsaid mold is in the form of a machine component.
 12. The process ofclaim 1 wherein Component (A) additionally contains a non-amineinitiated polyol having an equivalent weight of less than about 200 andwherein the weight ratio of non-amine initiated polyol to amineinitiated polyol is less than about 2:1.
 13. The process of claim 12wherein the ratio of non-amine initiated polyol to amine initiatedpolyol is less than about 1:1.